added nix devshell

flake.nix

@@ -0,0 +1,44 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+      };
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, rust-overlay }:
+    flake-utils.lib.eachDefaultSystem
+      (system:
+        let
+          overlays = [ (import rust-overlay) ];
+          pkgs = import nixpkgs {
+            inherit system overlays;
+          };
+          nativeBuildInputs = with pkgs; [
+            (pkgs.pkgsBuildHost.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml)
+
+            # Used by ffmpeg-next-sys to find ffmpeg libraries.
+            pkg-config
+            # Used by ffmpeg-next-sys via bindgen to generate bindings.
+            llvmPackages.libclang
+
+            # Without this bindgen will not be able to find libclang and won't be
+            # able to generate bindings.
+            rustPlatform.bindgenHook
+          ];
+          buildInputs = with pkgs; [
+            ffmpeg
+          ];
+        in
+        with pkgs;
+        {
+          devShells.default = mkShell {
+            inherit buildInputs nativeBuildInputs;
+          };
+        }
+      );
+}

rust-toolchain.toml

@@ -0,0 +1,4 @@
+[toolchain]
+channel = "stable"
+profile = "default"
+components = ["rust-analyzer"]